An optical transport network (OTN), as a core technology of a next generation transport network, is capable of implementing flexible scheduling and management of high-capacity services, and it increasingly becomes a mainstream technology of a backbone transport network.
With the rapid development of data services, the current OTN system can no longer satisfy the requirement of directly bearing multiple services with various rates. Aiming at the requirement, the Telecommunication Standardization Sector of the International Telecommunications Union (ITU-T) is discussing formulating a new flexible Optical channel Data Unit (ODUflex) frame to satisfy the requirement. The ODUflex frame may bear a packet service at any rate, and in this case, the ODUflex rate is opted to be n*1.24416 G, where 1≦n≦80. Since the ODUflex frame cannot directly pass a line interface, and needs to be encapsulated in an Higher Order Optical channel Data Unit (HO ODU) and to be transported through a Higher Order Optical channel Transport Unit (HO OTU). A current mapping manner of an ODUflex frame in an HO ODU uses a generic mapping procedure (GMP), where the ODUflex frame occupies some time slots of the HO ODU.
A packet service traffic has a property of not changing in real time, so in different time periods, an ODUflex channel is required to provide various bandwidths to satisfy various packet service traffic, and is required not to affect the normal transmission of the packet service while the bandwidth of the ODUflex channel is adjusted.
Therefore, how to achieve the lossless adjustment of ODUflex channel bandwidth has become a practical problem that is to be solved while a packet service is borne through an ODUflex channel.